Biological Aspects of Preferred Fish Species in White Volta at Pwalugu, Ghana: A pre-impoundment Study

Abstract

The socio-economic benefits derived from impounding rivers are extremely important but the ecological imbalances that are usually created in the process can be devastating. It is therefore imperative to understand some aspects of the biology of fishes before the impoundment of a river. This study was conducted to assess the length-weight relationship, condition factor, feeding, and reproductive ecology of fish species with high local market value. Biometric measurements were obtained from monthly samples of fish at two sites. Specimens were transported to the laboratory for gut and gonad analyses. Auchenoglanis occidentalis, Marcussenius senegalensis and Heterobranchus bidorsalis were the most preferred fish species. All three fish species recorded ‘b’ values less than 3 which implies they exhibited a negative allometric growth. Their condition factors (K) indicated they were in good health since K values were greater than 1. A. occidentalis and H. bidorsalis demonstrated a feeding habit comparable to that of an omnivore, whilst M. senegalensis presented a feeding habit that implied it was an invertivore. M. senegalensis registered the uppermost mean gonado-somatic index (GSI) (2.14 ± 0.83) whereas the highest mean fecundity (495 ± 450.96) was noted in A. occidentalis. This study contributed bio-ecological baseline information about the ichthyofauna prior to the damming of the reservoir in the Pwalugu area of the White Volta.